The controlled pulse waveform is newly applied in keyhole plasma arc welding process. Two additional descending slopes can guarantee stable and smooth transition of keyhole closing and opening periodically. To develop...The controlled pulse waveform is newly applied in keyhole plasma arc welding process. Two additional descending slopes can guarantee stable and smooth transition of keyhole closing and opening periodically. To develop a closed-loop control system for this special welding process, the key point is the determination of system input and output variables. The averaged efflux plasma voltage during a pulse cycle is defined as the characteristic variable reflecting the real keyhole dimension. Research and experiments are conducted to explore the relationship between the characteristic variable and weld pe^Cormance. Results show that alternated peak current can significantly change the keyhole dimension and the penetration. It is proposed that the keyhole average dimension is taken as the controlled variable, and the peak pulse current value and slopes are taken as control variables.展开更多
提出一种人体植入式医学装置电能传输新方法,该方法以人体组织作为耦合介质,通过体内、外耦合极板构建耦合电容,以耦合电场实现电能的无线传输。分析了人体组织的电学特性,设计了电能传输系统,并通过实验验证了该方法的可行性。实验中,...提出一种人体植入式医学装置电能传输新方法,该方法以人体组织作为耦合介质,通过体内、外耦合极板构建耦合电容,以耦合电场实现电能的无线传输。分析了人体组织的电学特性,设计了电能传输系统,并通过实验验证了该方法的可行性。实验中,通过36 cm2的耦合面积,穿越2 cm厚度的生物组织,可传输100 m W的可用电能,传输效率为35%~40%。该电能传输方式具有无电涡流致热、电磁干扰小、易于与医学仪器集成的优点,是人体植入式医学装置无线电能供给的新思路。展开更多
基金Acknowledgement The authors would like to thank the financial support for this research from the National Natural Science Foundation of China （ Key Program Grant No. 50936003）.
文摘The controlled pulse waveform is newly applied in keyhole plasma arc welding process. Two additional descending slopes can guarantee stable and smooth transition of keyhole closing and opening periodically. To develop a closed-loop control system for this special welding process, the key point is the determination of system input and output variables. The averaged efflux plasma voltage during a pulse cycle is defined as the characteristic variable reflecting the real keyhole dimension. Research and experiments are conducted to explore the relationship between the characteristic variable and weld pe^Cormance. Results show that alternated peak current can significantly change the keyhole dimension and the penetration. It is proposed that the keyhole average dimension is taken as the controlled variable, and the peak pulse current value and slopes are taken as control variables.
文摘提出一种人体植入式医学装置电能传输新方法,该方法以人体组织作为耦合介质,通过体内、外耦合极板构建耦合电容,以耦合电场实现电能的无线传输。分析了人体组织的电学特性,设计了电能传输系统,并通过实验验证了该方法的可行性。实验中,通过36 cm2的耦合面积,穿越2 cm厚度的生物组织,可传输100 m W的可用电能,传输效率为35%~40%。该电能传输方式具有无电涡流致热、电磁干扰小、易于与医学仪器集成的优点,是人体植入式医学装置无线电能供给的新思路。
